Ray is best known for his work on plants, and used his break-through scientific definition of a species to catalogue a vast number of plants from around the world. He was also very unusual in having studied a large number of plants out in the field, as well as relying on specimens sent to him by contacts across the globe.

He also coined terms that we use today such as petal and pollen.

Key Publications

• Cambridge Catalogue, 1660
• Catalogue of English Plants, 1668
• Table of Plants, 1668
• Catalogue of Foreign Plants, 1673
• New Method of Plants, 1682
• History of Plants, Vol 1 1686, Vol 2 1688 and Vol 3 1704
• Synopsis of British Plants, 1690
• Brief Dissertation, 1696

Catalogues of English, European and World Plants

In 1660 Ray published the Cambridge Flora, the first ever catalogue of an English county. This was followed by an ‘English Catalogue’ in 1670 and a catalogue of ‘Foreign Plants’ in 1673 based on his European tour. He also produced a ‘Flora of Britain’ in 1690 drawing together all his previous work.

Probably Ray’s most famous work is his ‘History of Plants’, published in 3 volumes in 1686, 1688 and 1704.  It was based on specimens Ray himself had collected in Britain and Europe, as well as specimens from around the world sent to him by a number of notable correspondents, including Hans Sloane from Jamaica. The first two volumes contained about 6,900 species, of which Ray knew over 6,000 from first-hand knowledge. The third volume contains about 10,000 new entries, from further reaches of the world including America, Africa, the Far East, The Philippines and the West Indies.

Classification and the Science of Botany

Prior to Ray there was no agreed language or procedure for describing for cataloguing plants. The existing lists of plants, or herbals, therefore contained many duplications, as well as many superstitions about how the plants should be collected for medicinal use. Ray’s breakthrough was realising that he needed to look at the whole structure of the plant when classifying them. He rejected the use of localities which were usually used to group plants, although he did note these in his catalogues. He states that he used the principal parts of the plant for classification – the flower, calyx, seed and seed-vessel, because they are constant, i.e. they can be reproduced from seeds, and do not vary like accidental characters, which he lists as size, scent, taste, colour and shape of the roots, number of angles of the stalk and variegation.

In order to increase his understanding of the structure of plants, he began to conduct some of the first recorded experiments on plants. Ray wrote a paper ‘On the Seeds of Plants’ in 1674, demonstrating that some plants have one seed-leaf and others two. We now refer to this as mono-cotyledons and di-cotyledons.